The present invention concerns a method of operating a machine for cutting stacks of material in sheets. The machine""s basic settings are established in accordance with parametric settings called machine parameters hereinafter,
A machine for cutting stacks of materialxe2x80x94paper, card, and similar material in particularxe2x80x94is known from EP 0 056 874 A2.
Once the machine parameters have been correctly established in such a machine, even relatively untrained people can use it properly without having to change the basic settings. The basic settings concern, for example, the speed of the saddle that advances the material being cut, the operation of the accelerating and decelerating ramps in conjunction with the advance of the saddle, the pressure exerted by the holdfast that secures the material in the vicinity of the cutting plane, etc. A machine with its basic settings established by way of the machine parameters alone, however, seldom cuts satisfactorily in individual cases. A wider stack of material must for example be subjected to higher pressure than a narrower stack. The stack-forwarding saddle can also be decelerated more rapidly by a larger stack than by a small stack. Optimizing the performance of a sheet-cutting machine by allowing the machine parameters to vary with the particular application has already been proposed. In this event of course, all other steps in the process will need to conform to the modified parameters. The results are not satisfactory because the operator must constantly readjust the machine to ensure proper cutting results case by case.
German GM 8 604 773 describes a computer-controlled paper cutter. Data and commands associated with the processing of paper by such a machine can be stored in an external memory. The memory is just an ordinary magnetic-tape cassette that programs comprising data and commands can be stored on. The machine can also supply reference data to the tape, allowing the programming to be modified. An advantage is that the same data can be employed for billing by obtaining them from the memory once a job has been completed.
A paper cutter with data storage is known from German OS 2 752 418. The memory is part of the processor that controls the machine. It comprises a permanent memory that stores the machine-control program and a variable memory that stores the data for the particular job. Reference data and particular functions can be selected from the data memory by way of a keyboard and deleted, replaced, or added to as desired.
The object of the present invention is an improved method of the aforesaid genus that will allow the operation of the machine to be adapted to the various conditions that occur during the job.
This object is attained in accordance with the present invention in that specific parameters (program parameters) are permanently assigned to an overall material-cutting program and in that individual parameters (routine parameters) are permanently assigned to paper-cutting routines within the overall program, whereby the machine parameters are stored and remain valid until modified or replaced by specifically requested routine parameters, and whereby the routine parameters are stored and remain valid until modified.